Heavy-duty loader for quick assembly on a tractor

ABSTRACT

A heavy-duty loader for quick assembly on a tractor includes an undercarriage which is secured to the tractor and remains therewith when the loader is detached. A clevis having a pivotable locking portion releasably engages an upright frame of the loader for mounting the loader on the tractor. A main frame has the work implement attached to its distal end and includes a pair of arms which are pivotally connected to the upright frame and pivoted with respect thereto by means of a pair of double acting hydraulic rams connected between the main frame and the upright frame. A detachable stand for the loader is cooperable with the aforementioned hydraulic rams to mount and dismount the loader without there being a forward or rearward movement of the tractor.

United States Patent [191 Miller 1 Oct. 14, 1975 HEAVY-DUTY LOADER FOR QUICK ASSEMBLY ON A TRACTOR Elmer L. Miller, R.R. No. 2, 'Larchwood, Iowa 51241 [22] Filed: May 31, 1972 [21] Appl. No.: 258,462

[76] Inventor:

3,554,396 l/l97l Demkiv 214/140 R 3,610,450 10/1971 Demkiv 214/140 3,612,311 lO/1971 Eidy et a1 214/140 OTHER PUBLICATIONS Trigg Catalog, Nov. 1, 1967, pp. 7, 8, 9, 22, 24 and oath.

Primary Examiner-Frank E. Werner Attorney, Agent, or Firml-1ill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson ABSTRACT A heavy-duty loader for quick assembly on a tractor includes an undercarriage which is secured to the tractor and remains therewith when the loader is detached. A clevis having a pivotable locking portion releasably engages an upright frame of the loader for mounting the loader on the tractor. A main frame has the work implement attached to its distal end and includes a pair of arms which are pivotally connected to the upright frame and pivoted with respect thereto by means of a pair of double acting hydraulic rams connected between the main frame and the upright frame. A detachable stand for the loader is cooperable with the aforementioned hydraulic rams to mount and dismount the loader without there being a forward or rearward movement of the tractor.

13 Claims, 13 Drawing Figures U.S. Patent Oct. 14, 1975 Sheet 1 0M 3,912,095

US. Patent Oct. 14, 1975 Sheet 2 of4 3,912,095

Sheet 3 of4 3,912,095

US. Patent Oct. 14, 1975 US. Patent Oct. 14, 1975 Sheet 4 of4 3,912,095

HEAVY-DUTY LOADER FOR QUICK ASSEMBLY ON A TRACTOR BACKGROUND OF THE INVENTION 7 main with the tractor when the loader is not in use and a loader frame assembly which is releasably engaged-by the undercarriage. 1

2. Description of the Prior Art Tractor loaders having a quick connect-disconnect feature are generally well known in the art. These loaders, however, are also generally constructed for light duty operation. In addition, these loaders require a forward movement of the tractor into the frame of the loader and cooperation between the tractor and the frame in order to mount the loader on the tractor. Similarly the tractor and frame are cooperable, with movement of the tractor out of the frame, in order to dismount the loader and place it in a free-standing storage position. Also, some of the known loaders utilize an engaging and latching mechanism which is somewhat complicated and which requires a certain amount of accuracy in moving the tractor forward in order to align the parts for engagement.

The primary object of the present invention is to provide a heavy-duty loader for quick assembly on a tractor wherein the loader itself, upon operation of hydraulic rams thereof, loads itself onto the associated tractor.

Another object of the invention is to provide a stand for a tractor loader so that the loader may be dismounted from the tractor and placed in a free-standing storage position. I

Another object of the invention is to provide a trac-' tor loader having simple releasable engagement means for securing the loader to thetractor.

Another object of the invention is to provide a heavyduty loader for quick assembly on a tractor which is adapted to prevent side sway during loading operations. v

The foregoing and other objects are realized through the provision of a tractor loader having an undercar riage which is bolted to and remains with an associated also remains with the tractor when the loader is placed in a free-standing position.

The loader also includes an upright frame having a pair of spaced vertical members which are releasably engaged by the clevis of each arm of the undercarriage. The upright frame also includes a pair of forwardly extending arms which are spaced apart a distance slightly greater than the transverse dimension of the tractor and have secured at the distal ends thereof a cross member which is received by the channel yoke when the loader is mounted on the tractor.-

The loader includes a main frame having a pair of spaced arms which are pivotally connected at one end to the respective vertical arms of the upright frame and at the other end to a work implement, such as a bucket. A pair of hydraulic rams are respectively connected on each side of the loader between a vertical arm and approximately the midpoint of the arms of the main frame and serve to raise and lower the main frame for loader operation and for mounting and dismounting the loader. The main frame also carries a further hydraulic ram which is connected between the main frame and the work implement for positioning the implement during loading operations and for aiding in mounting and dismounting the loader. I

The main frame is further provided with an extended pin for receiving a detachable stand. The stand includes an elongate vertical portion, a foot portion, and a portion which extends toward the forward end of the loader and includes an open clevis for receiving a cross member of the main frame. The foot portion of the stand serves as a pivot point in mounting and dismounting the loader and permits the loader to be moved with respect to the tractor.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of the invention, its organization, construction and'operation will be best understood from the following detailed descriptractor. The undercarriage includes a pair of" arms which are bolted to the rear axle housing on each side of the tractor and extent therefrom in the forward di rection of the tractor to a point forward of the tractor mounting guides for the loader.

The tractor is also supplied with a channel yoke which is secured, preferably by bolts,.to.- the forward end of thetractor. The channel yoke receives and registers a portion of the loader. in the proper position when the loader is mounted on the tractor. The channel yoke tion of a preferred embodiment thereof taken in conjunction with the accompanying'drawings, on which:

FIG. 1 is a pictorial view from the left-front showing a loader constructed in accordance with the principles of the present invention mounted on a tractor;

FIG. 2 is a side elevation of a loader according to the present invention;

FIG. 3 is a view looking from the underneath side of the loader toward the forward end;

FIG. 4 is a fragmentary view of a portion of the undercarriage, upright frame and main frame of a loader according to the invention showing a releasable clevis in the released position;

FIGS. 5-8 are diagrammatic elevational views showing various positions of the loader apparatus as the loader is mounted onto and dismounted from a tractor;

FIG. '9 is a detailed view of the undercarriage of a loader according to the present invention;

FIG. 10 is a fragmentary view showing details of the forward portion of the upright frame of a loader ac-' cording to the present invention;

FIG. 11 is a detailed view of the channel yoke which mounts at the forward end of a tractor;

FIG: 12- is a fragmentary view of the upper end of a stand of the loader of the present invention; and

FIG. 13 is a fragmentary view of a portion of the main frame specifically showing the extended pin for attaching the stand.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 14 and 13, a loader 11 is illustrated for use with a tractor 12 having rear wheels 13 and front wheels 14.

The loader 11 comprises an undercarriage 15 including a pair of spaced undercarriage arms 16 disposed on each side of the tractor and connected together by a member 17. The rear ends of the arms 16 are bolted as shown at 18 to the rear axle housing 19 of the tractor 12. The member 17 has a pair of upwardly extending weldments 40 (only one shown) which are bolted to respective sides of the tractor 12, as mounting guides.

The forward ends .of each of the undercarriage arms 16 carry clevis apparatus for releasable engagement of the loader. The clevis apparatus includes, on each side of the undercarriage, a first, stationary U-shaped bracket 20 secured to the arm 16, such as by welding, and forming a cavity for receiving a correspondingly shaped portion of the loader. A second U-shaped member 21 is pivotally attached to the arm 16 and may be swung into a position wherein it extends forwardly and upwardly to define a cavity similar to that defined by the U-shaped member 20. The U-shaped member 21 carries a quick-connect bolt assembly 23 for latching the member 21 to the member received therein, as will be set forth below.

The loader comprises an upright frame 24 including a pair of vertical member 25 each having wedge shaped ends 56, 57 to be received by the U-shaped members 20 and 21, respectively. The upright frame 24 includes a pair of spaced members 26 which extend from and are secured to respective ones of the vertical members 25. A cross member 27 is secured between the forward ends of the members 26 along with a second such transverse member 28. A pair of plates 29 are welded to the members 26, 27 and 28 for strength and rigidity. The plates 29, together with the associated members of the upright frame, prevent sway of the loader during loading by guiding the main frame (arms 31) and thereby prevents twisting of the tractor frame and attendant damage which may be caused by twisting.

The loader 11 also comprises a main frame 30 including a pair of spaced main frame arms 31 which are pivotally connected at oneend to the upper ends of the vertical members 25 of the upright frame 24 and extend adjacent the guide plates 29. The forward ends of the arms 31 are pivotally connected at 32 to a work implement, such as a bucket 33. The main frame 30 also includes a cross member 34 which extends between the arms 31, and an arm 35 which is secured to the cross member 34 and pivotally connected to the bucket 33 at 36. v

A pair of double acting hydraulic rams 37 are connected between respective ones of the arms 31 and the arms 25 for raising and lowering the arms 31. A furhter hydraulic ram 38 is connected between the assembly of the cross member 34 and the arm 35 and the bucket 33 for pivoting the bucket about the pivot defined by the connections at 32, 36. In FIG. 3 it can be seen that the main frame also includes a cross member 39 which is connected between the arms 31. In addition to strengthening the main frame, the cross member 31 is cooperable with a stand for supporting the loader in a free-standing position, as will be discussed below.

Refering to FIG. 11, a channel yoke is illustrated. The channel yoke is to be mounted so as to embrace the forward end of the tractor wherein the members 42 extend from the member 43 toward the rear of the tractor. The member 43 defines a channel 44 for receiving the cross member 27 illustrated in FIG. 10 when the loader is mounted on the tractor. A depending member or flange 45 is provided for securing the channel yoke to the front of the tractor and a pair of webs 46 are welded in place to add strength and rigidity to the channel yoke.

Referring to FIGS. 3, 12 and 13, the loader 1 l is provided with a detachable stand 47 having an elongate member 48 with a foot portion 49 for engaging a supporting surface. At the end of the member 48, opposite the foot portion 49, is a sleeve 50 for receiving a pin 51 (FIG. 12) which extends from and is secured to the arm 35. The stand 47 also includes an arm 51 which extends from the elongate member 48 and an arm 52 which extends from the elongate member 48 and is joined to the arm 51 by means of a plate 53. The distal ends 54 and 55 of the members 51 and 52, respectively, together with the plate 53, form an open clevis for receiving the cross member 39 which is secured between the arms 31 of the main frame 30.

Referring to FIGS. 5-8, the loader 11 is dismounted from the tractor as follows. First, the operator actuates the rams 37 to position the main frame approximately 4 feet above the ground. Next, the sleeved bore 50 of the stand 47 is placed over the pin 51 of the arm 35 with the open clevis extending about the cross member 39. The tractor operator then actuates the rams 37 to lower the main frame 30 until the foot portion 49 of the stand 47 contacts the ground. The tractor operator then actuates the ram 38 to tip the forward edge of the bucket 33 into engagement with the ground. The locking bolt 23 of each clevis of the undercarriage is then released and the respective U-shaped members 21 are swung forward and downward so as to clear the lower ends of the vertical members 25 and free the wedge shaped portion 57. The ram 38 is then operated to tip the forward end of the bucket inwardly whereby the foot portion 49 of the stand becomes a pivot point. The clearance between the cross member 39 and the open clevis permits the stand to move forward approximately 15 causing a shifting of the weight of the loader forward of the pivot point at the foot portion of the stand 49 to effect a walking action to the loader. This also creates a forward motion whereby the wedge shaped portion 56 moves out of the cavity formed by the correpsonding U-shaped member 20. By further continuous tipping of the forward end of the bucket upwardly, any desired height can be attained to permit subsequent rearward movement of the tractor away from the loader. The operator then disconnects the hydraulic hoses, for example by means of quick couplers and the tractor may be driven away from the loader.

To mount the loader on the tractor the reverse of the foregoing operation occurs. The tractor is driven into the loader and the quick couplers of the hdyraulic hoses are connected. The hydraulic ram 38 is operated to tip the forward end of the bucket down whereby the open clevis of the stand 47 permits the stand to move 15 rearwardly about the pivot defined by the foot porton 49 to effect a walking action to the loader. This transfers the weight of the loader toward the rear and forces the wedge shaped portions 56 into the respective cavities defined by the U-shaped members 20. At the same time the cross member 27 moves into the channel 44 of the channel yoke.

The weldment 40 which secures the undercarriage to the tractor 12 includes a plate 58 which is disposed upwardly and forwardly and has an edge 59 which is directed toward the clevis defined by the elements -21. The plate 58 and its edge 59 therefore act as a guide on each side of the tractor for guiding the lower ends of the vertical members during mounting so that the wedge shaped portions 56 of such lower ends become aligned with the cavities defined by the respective U-shaped members 20. The U-shaped member 21 may be locked into place by operation of the .bolt 23 and the stand may be removed from the loader. The loader is now ready for loading operations.

There has been disclosed herein a heavy-duty loader for quick attachment to and detachment from a tractor. The loader includes a detachable stand which may be utilized in cooperation with the hydraulic rams of the loader to move the loader from or onto a tractor without requiring that the tractor cooperably engage the stand. Further, the loader apparatus includes means for guiding, aligning and positioning the loader with respect to the loader undercarriage carried by the tractor and a channel yoke assembly carried by the tractor so that the mounting operation is a relatively simple matter.

Although l have described my invention by reference to a specific illustrative embodiment, many changes and modifications of my invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. It is therefore to be understood that I intend to include within the patent warranted hereon all such changes and modifications as may reasonably and properly be included within the scope of my contribution to the art.

I claim:

1. A loader for use with a tractor, comprising:

a first frame secured to the tractor;

a second frame adapted to receive the tractor and carry a work implement, said second frame including a pin extending therefrom, and a cross member adjacent the forward end thereof;

means for releasably attaching said second frame to said first frame to mount the loader on thetractor; and

a detachable stand for placing said first frame in a free-standing position supported by said stand and said work implement, said stand comprising an elongate portion, a foot portion at one end of said elongate portion, a bore for receiving and pivoting about said pin, and means extending from said elongate portion defining an open clevis for'receiving said cross member,'said clevis defining means including a first member for limiting movement of said foot portion to positions to the rear of vertical and a second member for limiting movement of said loader with respect to said stand to approximately 15.

2.. ,A loader for use on a tractor, comprising:

an undercarriage including a pair ofspaced undercarriage arms on respective sides ofthe tractor, each of said undercarrige arms including means for attaching the rear end of the arm to the rear axle housing of thetractor, a first U-shaped member secured to said arm at an angle' to define therewith a first wedge-shaped opening and a second U-shaped member pivotally secured to said arm and pivotal to define therewith a second wedge-shaped opening, an undercarriage cross member disposed beneaththe tractor and connecting the forward ends of said arms, and a pair of guides secured to said undercarriage cross member adjacent respective ones of said arms, each of said guides including means for securing said guide to the tractor and a guide member having an edge oriented toward the forward end of the arm at an angle both transverse and longitudinal of the loader;

a channel yoke including first and second members secured to opposite sides of the forward end of the tractor and a channel member connecting said first and second members and defining a forwardly opening channel across the front of the tractor;

an upright frame including a pair of spaced vertical arms each having a pair of wedge-shaped portions to be received by said U-shaped members, a pair of spaced arms extending forwardly from said vertical arms and a third arm connecting the forward ends of said forwardly extending arms to define an opening for receiving the tractor, said third arm being received in the channel defined by said channel member;

main frame including a pair of spaced main frame arms pivotally connected at one end to respective ones of said vertical arms and adapted for pivotal connection to a work implement at the other ends,

a first cross member connecting said pair of main frame arms, a third main frame arm connected at one end to said'first cross member and adapted for pivotal connection at its other end to the work implement, a second cross member connecting the three mentioned main frame arms adjacent the forward ends thereof, and a pin extending from said third main frame arm transversely of said loader; a pair of double acting hydraulic rams connected respectively between a vertical member of said upright frame and the respective main frame arm pivotally connected thereto and operable to raise and lower said main frame; at least one double acting hydraulic ram adapted for connection to the work implement and connected to said main frame and operable to pivot the work implement about its pitoval connection to said main frame arms; and a detachable stand including a foot portion for engaging a supporting surface, an elongate porton extending from said foot portion and having a sleeve for pivotally receiving said pin, a pair of forwardly extending members connected to said elongate portion, and a plate connecting said forwardly extending members to define therewith an open clevis for receiving said second cross member of said main frame, the distance between said forwardly extending members at the open clevis being greater than the corresponding dimension of said second cross member to define approximately 15 of movement of said stand about said pin for insuring shifting the weight of said loader forward of said foot portion during dismounting of said loader. 3. in a loader of the type wherein the loader defines an opening for receiving a tractor that remains stationary during positionment of the loader on said tractor, a loader frame which carries a work implement, a pivotal connection between the loader frame and the work implement, a pivotally mounted stand connected to the frame from which the work implement can support the loader in a free-standing condition,

the frame having rearward extending arms supportable on the tractor,

the tractor having loader frame channel shaped support means mounted on its forward end,

cross arm means on the loader engageable with said channel shaped support means for supporting the loader frame at the forward end of the tractor,

detachable coupling means for securing the arms of the loader frame to the tractor,

the weight of the loader being so balanced on the stand and on the tractor that when said detachable coupling means is detached, the weight of the loader continues to be supported by the stand and the tractor, and

means for shifting the weight of the implement outwardly away from the tractor to cause the loader frame to pivot about the stand thereby disengaging in first a relatively rectilinear path and then subsequently elevating in an arcuate path the previously supported rearward ends of the arms from the tractor and to disengage the cross arm means from said loader frame channel shaped support means and to move the loader into a free-standing position.

4. In a loader of the type wherein the loader definesan opening for receiving a tractor, a pivoted frame which carries a work implement, a stand connected to the frame which with the work implement supports the loader in a free-standing condition, and means operable to pivot the loader about the foot of the stand to mount the loader on or dismount the loader from the tractor, the improvement comprises:

a pivotal connection of said stand and said pivotal frame to form a second pivot for said loader; and

means coupling said stand and said pivotal frame to permit limited pivotal movement about said second pivot an amount sufficient to shift the weight of the loader forward and then upward of the pivot at the foot of the stand,

said coupling means includes a cross member adjacent the forward end of said pivotal frame and members included in said stand and extending to definean open clevis for receiving said cross member, said clevis having a greater dimension'than said cross member to define limits of pivotal movement.

5. A loader for use with a tractor, comprising:

an undercarriage to be secured to the tractor, an upright frame adapted to receive the forward end of the tractor, and a main frame pivotally connected to said upright frame at one of its ends and adapted for pivotal connection to a work implement at its other end;

a detachable stand releasably connected to said main frame and having a foot portion for engaging a supporting surface and acting as a pivot when mounting and dismounting said loader;

means connected between said upright frame and said main frame and connectable between said main frame and the work implement for positioning said work implement and said main frame with respect to said upright frame whereby said loader is pivoted about said foot portion of said stand for mounting and dismounting; and

said undercarriage including means for releasably securing said upright frame thereto, and guide means for guiding said upright frame toward said releasable securing means,

said undercarriage includes a pair of spaced arms each secured to and carried by the tractor, and said releasable securing means includes, on each of said arms, a first member secured to said arm and defining a first opening for receiving said upright frame, a second member pivotally secured to said arm and pivotal to define a second opening for receiving said upright frame, means for latching said second member about said upright frame.

6. A loader for use with a tractor, comprising:

an undercarriage to be secured to the tractor, an upright frame adapted to receive the forward end of the tractor, and a main frame pivotally connected to said upright frame at one of its ends and adapted for pivotal connection to a work implement at its other end;

a detachable stand releasably connected to said main frame and having a foot portion for engaging a supporting surface and acting as a pivot when mounting and dismounting said loader;

means connected between said upright frame and said main frame and connectable between said main frame and the work implement for positioning said work implement and said main frame with respect to said upright frame whereby said loader is pivoted about said foot portion of said stand for mounting and dismounting; and

said undercarriage including means for releasably securing said upright frame thereto, and guide means for guiding said upright frame toward said releasable securing means,

said undercarriage includes a pair of spaced arms each secured to and carried by the tractor on respective sides thereof, and said guide means includes on each of said undercarriage, a guide member having an edge directed downwardly toward the rear of the tractor and outwardly toward the respective undercarriage arm.

7. A loader according to claim 6, wherein said undercarriage includes a cross member connecting said arms and extending beneath said tractor, said guide means mounted on said cross member.

8. A loader according to claim 7, comprising means securing said guide means to the tractor.

9. A loader for use with a tractor, comprising:

an undercarriage to be secured to the tractor, an upright frame adapted to receive the forward end of the tractor, and a main frame pivotally connected to said upright frame at one of its ends and adapted for pivotal connection to a work implement at its other end;

a detachable stand releasably connected to said main frame and having a foot portion for engaging a supporting surface and acting as a pivot when mounting and dismounting said loader;

means connected between said upright frame and said main frame and connectable between said main frame and the work implement for positioning said work implement and said main frame with respect to said upright frame whereby said loader is pivoted about said foot portion of said stand for mounting and dismounting; and

said undercarriage including means for releasably securing said upright frame thereto, and guide means for guiding said upright frame toward said releasable securing means,

said main frame includes a cross member adjacent the forward end thereof, and a pin extending from said main frame rearwardly of said cross member, and said stand includes a bore for receiving said pin and means defining an open clevis extending to receive said cross member.

10. A loader according to claim 9, wherein said means defining an open clevis include means defining a movement of said stand as-said cross member is permitted to move within the limits of said open clevis as said stand pivots about said pin.

11. A loader for use with a tractor, comprising:

an undercarriage to be secured to the tractor, an upright frame adapted to receive the forward end of the tractor, and a main frame pivotally connected to said upright frame at one of its ends and adapted for pivotal connection to a work implement at its other end;

a detachable stand releasably connected to said main frame and having a foot portion for engaging a supporting surface and acting as a pivot when mounting and dismounting said loader;

means connected between said upright frame and said main frame and connectable between said main frame and the work implement for positioning said work implement and said main frame with respect to said upright frame wherebysaid loader is pivoted about said foot portion of said stand for mounting and dismounting; and

said undercarriage including means for releasably securing said upright frame thereto, and guide means for guiding said upright frame toward said releasable securing means, said upright frame includes wedge-shaped portions and said first and second members define wedge-shaped openings to receive said wedge-shaped portions.

12. The loader of claim 11 further characterized by 5 the upright frame and the main frame collectively comprising a loader frame and with the loader frame having rearward extending arms supportable on the tractor,

the weight of the loader being so balanced on the stand and on" the tractor that when the releasable securing means is detached, the weight of the loader continues to be supported by the stand and the tractor, and

means for shifting the weight of the implement outthe upright frame and the main frame collectively comprising a loader frame and with the loader frame having rearward extending arms supportable on the tractor,

the weight of the loadr being so balanced on the stand and on the tractor that when the releasable securing means is released, the weight of the loader remains balanced with respect to the tractor, and

means for shifting the weight of the implement outwardly away from the tractor to cause the loader frame to pivot away from the tractor thereby disengaging in first a relatively rectilinear path and'then subsequently elevating in an arcuate path the previously supported rearward ends of the arms from the tractor and to move the loader into a freestanding position. 

1. A loader for use with a tractor, comprising: a first frame secured to the tractor; a second frame adapted to receive the tractor and carry a work implement, said second frame including a pin extending therefrom, and a cross member adjacent the forward end thereof; means for releasably attaching said second frame to said first frame to mount the loader on the tractor; and a detachable stand for placing said first frame in a freestanding position supported by said stand and said work implement, said stand comprising an elongate portion, a foot portion at one end of said elongate portion, a bore for receiving and pivoting about said pin, and means extending from said elongate portion defining an open clevis for receiving said cross member, said clevis defining means including a first member for limiting movement of said foot portion to positions to the rear of vertical and a second member for limiting movement of said loader with respect to said stand to approximately 15*.
 3. In a loader of the type wherein the loader defines an opening for receiving a tractor that remains stationary during positionment of the loader on said tractor, a loader frame which carries a work implement, a pivotal connection between the loader frame and the work implement, a pivotally mounted stand connected to the frame from which the work implement can support the loader in a free-standing condition, the frame having rearward extending arms supportable on the tractor, the tractor having loader frame channel shaped support means mounted on its forward end, cross arm means on the loader engageable with said channel shaped support means for supporting the loader frame at the forward end of the tractor, detachable coupling means for securing the arms of the loader frame to the tractor, the weight of the loader being so balanced on the stand and on the tractor that when said detachable coupling means is detached, the weight of the loader continues to be supported by the stand and the tractor, and means for shifting the weight of the implement outwardly away from the tractor to cause the loader frame to pivot about the stand thereby disengaging in first a relatively rectilinear path and then subsequently elevating in an arcuate path the previously supported rearward ends of the arms from the tractor and to disengage the cross arm means from said loader frame channel shaped support means and to move the loader into a free-standing position.
 4. In a loader of the type wherein the loader defines an opening for receiving a tractor, a pivoted frame which carries a work implement, a stand connected to the frame which with the work implement supports the loader in a free-standing condition, and means operable to pivot the loader about the foot of the stand to mount the loader on or dismount the loader from the tractor, the improvement comprises: a pivotal connection of said stand and said pivotal frame to form a second pivot for said loader; and means coupling said stand and said pivotal frame to permit limited pivotal movement about said second pivot an amount sufficient to shift the weight of the loader forward and then upward of the pivot at the foot of the stand, said coupling means includes a cross member adjacent the forward end of said pivotal frame and members included in said stand and extending to define an open clevis for receiving said cross member, said clevis having a greater dimension than said cross member to define limits of pivotal movement.
 5. A loader for use with a tractor, comprising: an undercarriage to be secured to the tractor, an upright frame adapted to receive the forward end of the tractor, and a main frame pivotally connected to said upright frame at one of its ends and adapted for pivotal connection to a work implement at its other end; a detachable stand releasaBly connected to said main frame and having a foot portion for engaging a supporting surface and acting as a pivot when mounting and dismounting said loader; means connected between said upright frame and said main frame and connectable between said main frame and the work implement for positioning said work implement and said main frame with respect to said upright frame whereby said loader is pivoted about said foot portion of said stand for mounting and dismounting; and said undercarriage including means for releasably securing said upright frame thereto, and guide means for guiding said upright frame toward said releasable securing means, said undercarriage includes a pair of spaced arms each secured to and carried by the tractor, and said releasable securing means includes, on each of said arms, a first member secured to said arm and defining a first opening for receiving said upright frame, a second member pivotally secured to said arm and pivotal to define a second opening for receiving said upright frame, means for latching said second member about said upright frame.
 6. A loader for use with a tractor, comprising: an undercarriage to be secured to the tractor, an upright frame adapted to receive the forward end of the tractor, and a main frame pivotally connected to said upright frame at one of its ends and adapted for pivotal connection to a work implement at its other end; a detachable stand releasably connected to said main frame and having a foot portion for engaging a supporting surface and acting as a pivot when mounting and dismounting said loader; means connected between said upright frame and said main frame and connectable between said main frame and the work implement for positioning said work implement and said main frame with respect to said upright frame whereby said loader is pivoted about said foot portion of said stand for mounting and dismounting; and said undercarriage including means for releasably securing said upright frame thereto, and guide means for guiding said upright frame toward said releasable securing means, said undercarriage includes a pair of spaced arms each secured to and carried by the tractor on respective sides thereof, and said guide means includes on each of said undercarriage, a guide member having an edge directed downwardly toward the rear of the tractor and outwardly toward the respective undercarriage arm.
 7. A loader according to claim 6, wherein said undercarriage includes a cross member connecting said arms and extending beneath said tractor, said guide means mounted on said cross member.
 8. A loader according to claim 7, comprising means securing said guide means to the tractor.
 9. A loader for use with a tractor, comprising: an undercarriage to be secured to the tractor, an upright frame adapted to receive the forward end of the tractor, and a main frame pivotally connected to said upright frame at one of its ends and adapted for pivotal connection to a work implement at its other end; a detachable stand releasably connected to said main frame and having a foot portion for engaging a supporting surface and acting as a pivot when mounting and dismounting said loader; means connected between said upright frame and said main frame and connectable between said main frame and the work implement for positioning said work implement and said main frame with respect to said upright frame whereby said loader is pivoted about said foot portion of said stand for mounting and dismounting; and said undercarriage including means for releasably securing said upright frame thereto, and guide means for guiding said upright frame toward said releasable securing means, said main frame includes a cross member adjacent the forward end thereof, and a pin extending from said main frame rearwardly of said cross member, and said stand includes a bore for receiving said pin and means defining an open clevis extending to receive said cross member.
 10. A loader accoRding to claim 9, wherein said means defining an open clevis include means defining a 15* movement of said stand as said cross member is permitted to move within the limits of said open clevis as said stand pivots about said pin.
 11. A loader for use with a tractor, comprising: an undercarriage to be secured to the tractor, an upright frame adapted to receive the forward end of the tractor, and a main frame pivotally connected to said upright frame at one of its ends and adapted for pivotal connection to a work implement at its other end; a detachable stand releasably connected to said main frame and having a foot portion for engaging a supporting surface and acting as a pivot when mounting and dismounting said loader; means connected between said upright frame and said main frame and connectable between said main frame and the work implement for positioning said work implement and said main frame with respect to said upright frame whereby said loader is pivoted about said foot portion of said stand for mounting and dismounting; and said undercarriage including means for releasably securing said upright frame thereto, and guide means for guiding said upright frame toward said releasable securing means, said upright frame includes wedge-shaped portions and said first and second members define wedge-shaped openings to receive said wedge-shaped portions.
 12. The loader of claim 11 further characterized by the upright frame and the main frame collectively comprising a loader frame and with the loader frame having rearward extending arms supportable on the tractor, the weight of the loader being so balanced on the stand and on the tractor that when the releasable securing means is detached, the weight of the loader continues to be supported by the stand and the tractor, and means for shifting the weight of the implement outwardly away from the tractor to cause the loader frame to pivot away from the tractor thereby disengaging in first a relatively rectilinear path and then subsequently elevating in an arcuate path the previously supported rearward ends of the arms from the tractor and to move the loader into a free-standing position.
 13. The locader of claim 11 further characterized by the upright frame and the main frame collectively comprising a loader frame and with the loader frame having rearward extending arms supportable on the tractor, the weight of the loadr being so balanced on the stand and on the tractor that when the releasable securing means is released, the weight of the loader remains balanced with respect to the tractor, and means for shifting the weight of the implement outwardly away from the tractor to cause the loader frame to pivot away from the tractor thereby disengaging in first a relatively rectilinear path and then subsequently elevating in an arcuate path the previously supported rearward ends of the arms from the tractor and to move the loader into a free-standing position. 